Method of and apparatus for distilling and fractionating oil



D. G. BRANDT May 14, 1929.

METHOD OF AND APPARATUS FOR DISTILLING AND FRACTIONATING OIL 4 Sheets-Sheet] 1 Filed April 8, 1921 FRALT/QWATING COL OIL mm;-

4 L ms 0!? m Pan cmcwr 4 Sheets-Sheet '2 May 14, 1929. o. s. BRANDT METHOD OF AND APPARATUS FOR D ISTILLING AND FRAGTIONATING OIL Filed April 8, 1921 Inky 6,:

May 14, 1929. 33. 3, METHOD OF AND APPARATUS FOR DISTILLING AWD FRAbTI O NATING OiL 7 Filed. Aprii a, 11.921 4 Sheets-$heet 5 May 14, 1929.

D. 5. BRANDT 1,713,255

METHOD OF AND APPARATUS FOR DISTILLING AND FRACTIONATING OIL Fild April 8 1921 4 Sheets-Sheet 4 OIL PUMP 42 GAS PUMP 8 -7TILL 75/ [6 m4 m6 m8 9? pors are slowly driven ofl from a body of oil,

Patented May 14, 1929.

UNITED STATES PATENT oFFrcE.

.DAVID G. BRANDT, or WESTFIELD, IvEw annsnv, Assrenon, BYnvrEs'N'E AssIGN- MENTS, T0 HEAT TREATINGCOMPANY, on NEW YORK, N. Y., A CORPORATION OF DELAWARE. I

METHOD OF AND APPARATUS FOR DISTILLING AND FRACTIONATING OIL.

Application filed April 8,

This invention relates to the -distillation of liquid mixtures, and more particularly to a Crude petroleum oil is a common example of a liquid which consists of a mixture of a large number -of liquid constituents that may be separated by distillation. The principal products obtained from petroleum distillations are products which are composed of groups of liquid hydrocarbons that are roughly grouped together, in accordance with the initial and final boiling points of the constituents in each group. 7

Most of the crude oil distillation is carried out by an intermittent process in which vathe vapors condensed, and the condensates within a predetermined bollmg point range separately collected.- These condensates,

. l10\VGVO1,Hl'G not suitable for commercial uses but must be chemically purifiedv and redistilled several times to secure-the proper boiling' point and the gravity for each fraction to prepare them for commercial use.

By a more recent process oil is fractionally distilled by being passed in succession through temperatures and a distinct fraction is removed from each still.

over, are very rough cuts and must be chemically purified and redistilled several times to prepare them forcommercial use.

In none of the oil distilling processes in commercial use has there been any attempt to obtain products having sharply'defined boils ing point and gravity limits in the first disf tillation, which would be'suitable for 100111- mercial uses after the products have been chemicallytreated.

One object of the present invention is to provide a process of and apparatus for. continuously distilling a liquid mixture such as petroleum oil by which approximately the entire range of fractions in the oil may be simultaneously separated within sharply. defined limits in a single operation.

The distillation processesincommon useemploy very ineflicient heating methods and also lose enormous quantities of heat in con- (lensing tl e vapors and cooling the conden- These fractions, how- This entails a large heat lossand re- 1921. Serial No 459,678.

quires the use of large quantities of water for cooling purposes. Further, a long continued heating'of oil in'a large body'to progressively higher temperatures tends to overheat and to decompose the'oil to cause losses due to the 7 formation of tar and unsaturated compounds and incondensable gases. t

In dlstilhng Oll in accordance with the prescut invention, the incoming oil for distilla tlon 1s preheated 1n acting as a cooling niedium to condense the vapor fractions being formed, and to absorb the sensible heat ofthe condensates. The heat interchanged between i thevapor and the condensates and the 0il,-supplies a largeportion of the heat necessary for vaporizing the oil. At the same time aheat transferring gas is passed through the oil in parallel current with the vapors, and this gas assistsin supplying the-heat of the va'porizanon of the 011, while maintaining partial pressures in the distillation chamber, which materially reduce theboiling pointsrof the vapor fractions. I v V WVith this in view another object of the-invention is toprovidea process of and appar'a tus for distilling petroleum by. which fractional distillation may be carried out with a a series of cylindrical stills. Thestills in the series are maintained at progressively higher minimum consumption and loss of heat.

Another object of the invention is to pro vide aprocess of and apparatus for fractionally distillingoil at temperatures substantially below the normal atmospheric pressure boiling temperatures, whereby long continued high temperature heating of the oil may be avoided and the formation of a large amount of unsaturated compounds and fixed gases 'may be avoided.

ith these and other objects in view, the invention consists m'the improved processof and apparatus for dist lling oil hereinafter described and particularly defined in the claims.

Fig. 2 is a perspective viewin front elevation diagrai'nmatically illustratingthe construction and arrangement of thefractiona-tmg chambers of the distilling unit; I

Fig. 3 1s a vertical sectional view. of the .fractionating chambers of the distilling unit;

F 4 is a vertical sectional view of the fractionating chambers taken on the line H of Fig. 3, and

wardly in succession through a series of vaporizing chambers, and then conducted into a heating still. Aspecilic oil fraction is vaporized in the still and in each chaiiiberand the vap or fraction is then passed upwardly into a condenser in the chamber, next above that chainber in which the vapor is formed, to be condensed by the cooler oilv in this chamber. To

, maintain progressively increasing temperatures in the various chambers from the top toward the bottom of the fractionating column, three distinct heating means are employed. First, a gas is circulated in a closed cycle through the heating still and then through the chan'ibers in succession in a path countercurrent to the path of the flow of the oil through the chambers and still. The is preheated before entering the still and then passes from i the still, together with the vapors formed therein into the condenser of the lowermost chamber of the fractionating column. After passing through the condenser the gas is bubbled through the oil in the same chamber in which the condenser is in contact with the oil being treated and then flows through connections into the condenser of the next higher chamber, and so on through the entire fractienating column.- In this way the sensible heat of the gas is gradually absorbed by the oil in the various chambers.

The second means of maintaining the temperatures in the various chambers consists in mixing the vapors formed in the still and in each chamber with the heat transferring gas, and passing the vapors into the condenser in the chamber next above that in which the vapor is formed. The teii'iperature differential between the oil in adjacent chambers serves to condense the greatest portion of the vapors passii'ig through the condenser, and thereby the heat of vaporization, or heat of condensation of the vapors is imparted to the oil to raise its temperature or vaporize a lower boiling point fraction.

'The third means of maintaining the progressive gradation in temperatures in the chan'ibers consists in collecting the residue from the still and the condensates formed in the chambers, and circulating them in separate circuits upwardly through the f-ractionating column in apath countercurrent to theadvance of the oil through the fractionating column. By this means the sensible heat of the residue and the condensates is imparted to '7 the oil being distilled.

By the three forms of heating means it will be noted that the high temperature gas, the high temperature vapors, the high temperature residue and the high temperature condensates are brought into intimate heat transferring relationship with the oil which needs to be vaporized at a high temperature. These high temperature mediaare therefore available at the place where the hi gli temperature is needed. As the gas, residue, and condensates advance together upwardly through the fractionating column, they are all re duced to-substantially the same temperature and the temperature is gradually reduced until they are discharged from the fractionating column at substantially the same temperature as that of the incoming oil.

To carry out the process above referred to in the apparatus shown in the drawings,.

in succession through chambers 20, 22, 2d, 26

and 28, formed in thecolumn 18 by. means of transverse partitions 30. The oil enters the chamber 16 through the pipe 14: at the bottom of the chambei and overflows from the chamber 16 through a pipe 32, which is connected at itsupper end with the upper portion of the chamber 16 and at its lower end with the bottom of the chamber 20. The oil overflows from the chambers 20 to 28 inclusive through overflow'pipes 34 having a construction the same as the construction of the overflow pipe 32. The upper ends of the overflow pipes and E l are connected to the chambers a short distance below the partitions 30, to provide a space in the upper part of each chamber in which the vapors formed in the chamber may be collected in order to be passed upward-- ly into the next or preceding chambers to be condensed. The oil which-is not vaporized in the bottom or last chamber 28 of the fractionatin'g column flows out of the chamber through a pipe 36, and is conducted into the bottom of a heating still 38 (Figs. 1 and 5). In the still 38 the oil is reduced to any desired gravity to form a residue which ordinarily would be classed as a fuel oil or cylinder stock.

To assistin maintaining a distinct iliiji'erentiul in the temperatures of the oil in any two adjacent vaporizing chambers, and also to assist in vaporizing the oil at subnormal tem )eratures a as is circulated through the still and chambers in a closed cycle. 1 cthis end gas which preferably consists of a gas 50. After passing through coil 46. the pro-- heated gas enters the still 88 through a pipe 52 and is distributed throughout the body of the oil in the still by means of a series of perforated distributing pipes 54. Thegas leaving the pipes 54 bubbles upwardly through the oil and is collected in the upper part of thestill, together with any vapors formed in the still. The vapors formed in the still.

are absorbed or mixed with the gas and. the

gas-vapor mixture is then conducted through a-pipe 56 into a condenser 58 positioned in the chamber 28 of the fractionating column 18. The condenser 58 consists of a manifold 60, (Figs; 2 and 3) posltloned on the outside of the front end of the column, a manifold '62 positioned within the column, and a series of tubes 64 connected between the manifolds 60 and 62. The manifold 60 is provided with a partition 66 whichdivides it into :an inlet section and an outlet, section. v The gas- .vapor mixture from the still. flows into the inlet section of the manifold 60 through the pipe 56, then passes through approximately half of the tubes .64 to the manifold 62 and returns to the outlet section of the manifold 60 through the remaining tubes 64c. From the outlet section of the manifold the gas,

"together with any uncondensed vapors passes through an inverted U tube 68 intoa distributor70, positioned in;the bottom of the chamber 28. The distributor 70 consists of an inverted pan having a series of holes covering its bottom andarranged to distribute the gas-vapor mixtures throughout the body of oil within the chamber 28. The holes in the distributor are so designed to force the gas to pass upwardly into the oil and to prevent the oil from flowing downwardly into thepan while the fraotionating column is in operation. The gas-vapor mixture passes upwardly through the chamber 28in the form of line bubbles to impart its 7 heat to the oil, and assist in vaporizing the oil within the chamber; Any vapor formed in the chamber is mixed with the gas, and

the gas-vapor mixture collects in the top of the chamber from where it is withdrawn through a collecting pipe 72. The pipe 72 passes outwardly through the front end. of

the fractionating column and is connected with an inlet section of a manifold T l of a condenser 7 6 "mounted within the chamber 26. The condenser 76 has thesame construction as the condenser 58 and acts to conduct the gas-vapor mixture in a forward and return path through the chamber 26. The gasvapor mixture leaves the condenser through an inverted U pipe 78 and passes into adistributor 80 mounted in the bottom of chamber 26. The U pipe 78 and the distributor 80,

have the same construction as the pipe 68 i and the. distributor 7 0,.respectively. In a like manner the, gas passes from the chamber 26 upwardly through the condensers 82, 84:,

which the gas is circulated.

pipe 100 which is connected to thegas pipe .40 leadingto the pump {12. A valve outlet 102 is provided in the pipe 100 by which excess gas which is accumulated in the distilling operation may be continuously or, intermittently removed from the closed cycle in The. sensible heat of the liquid residue from the still38 and the latent heat and sensible heat ofthe condensates collected in each of the chambers is imparted to the oil undergoing distillation, to. assist in distillingthe oil with a minimum expenditureof heat; To accomplish this the gas introduced into the still by the pump 42jis maintained.

under suflicient pressures, so that the residue from the still will overflow through a pipe 104 to a trap 106, and be forced from the trap through a separate circuit 108, upwardly through each of the chambers. of the frac tionating tower. The circuit 108, see Figs. 1, 2, 3 and 4, consists of a coil within each of the chambers and connecting pipes 112, connecting the coils of the respective cham- V bers.) The path ofthe circuit throughchamber 26 may be modified byv means of a short circuit tube 114, which is connectedlmtween the pipe ,112 and the lasttube of the coil 110. Valves .116 and-118 are provided respectlvely in the pipesll t and 1,12, whereby through the chamber 26 maybe varied so that a part willflow through the entire coil 110, or all or a part may be by-passed to. the

last tube of the'coil 110.

the volume and pathotthe residue flowing.

The condensate which is formed in. the condenser 58 is held back by the U tube 68 and passes into a trap 120 from which it is forced? by the pressure in the chamber through a condensate circuit- 122, passing through each of the chambers above the chamber 26. The

circuit 122 has a construction similar to the circuit 108, beingprovided witha coilin each chamber and with connecting pipesbetweenthe coils. A short-circuit pipe 124and valves 126 and 128 are provided bywhich the path of fiow of the condensate may be varied in the coil within the chamber 24. The condensates from the chambers 24,22,20 and 16 I are removed from their respective condensers 82, 84, 86- and 88 in the same mannerthat condensate is removed from the condenser,58.

These condensates are passed respectively intot-raps 130, 132, 134, 136 and 138,which are connected respectively to the inverted U pipes for each of the condensers within their chambers 2416. V The traps 130 to 136,-inclusive, are connected respectively with condensate circuits 140, 142, 144 and 146, each circuit leading the condensate through all of the chambers above or preceding the chamber in which the condensate is formed. The condensate from trap 138 is removed through pipe 14-8 to a receiving house.

By this construction it will be noted that each chamber contains a condensate circuit coil for each chamber succeeding it or located below it, as well as a circuit coil for the residue from the still. The pressure maintained by the gas circuit in each of the chamhers is sufficient to force the'condensate from the respective chambers upwardly through the fractioning column. The condensates preferably may be discharged through pipes 149 passing through the rear end of the chamber 16, see Figs. 1 and 3, from which they may pass to a receiving house and the storage tanks. It maybe desirable to remove the high cold test cuts from chamber 20 or a chamber having a higher temperature than the chamber 16. condensates may be taken out of chamber 20 through pipes 151. When the vapors are passing through the condensers in the various chambers, those vapors which are condensable at the temperature of the oil within the chambers will be separated and any uncondensedvapors will be bubbled through the oil in that chamber to pass to prece ling chamber having cooler oil.

By the separate condensate and residue circuits in the various chambers approximately all. ofthe sensible heat in the condensates and residue is returned to the incoming oil. The condensates form a very large proportion of the oil originally entering for distillation, and therefore if the sensible heat in these con- 'densates is lost, a very large portion of the heat required for distillation is lost to the process. By the apparatus outlined above the sensible heat of the condensates and the residue is effectively returned to the oil undergoing distillation.

Tlieconstruction'of the fractioning tower permits a comparatively large volume ofthe oil to be handled with a relatively small apparatus. By having a series of chambers separated from one another by partitions, there no radiation loss except at the sides of the column. Further, a heat transfer is maintained between the partitions'toassist in cffecti ng distillation.

When the gas conducted through the condensers of each chambernnder pressure, it is not necessary that the condensers should be so perfectly constructed as to prevent all leaks, because the gaspressure within the condensers is slightly higher than the pressure of the oil in the chambers surrounding the condenser, and, therefore, any leakage of the condenser will allow gas to flow from the condenser into the oil. This leakage will not interfere in any way with the operation of the still. I V

' With the process of an apparatus for distilling oil outlined above it will be noted that approximately all of the heat of the vaporization of the oil fractions, and approximately all of the sensible heat of the condensates will be returned to the process. The only heat thatwill be needed to be supplied to the process will be that which will be required to provide for radiation losses, that required to maintain the temperature differential between the oil in adjacent chambers, and the heat of vaporization of the last fraction of the oil. The use of a gas circuit permits the oil to be vaporized at comparatively lower temperatures, so that there is no danger of scorching, burning or cracking the oils, and the formation of fixed gases is reduced to a minimum. Further, the gas circuit furnishes an ideal medium by which the heat may be transferred to the oil, and the oil kept in active agitation to assist the heat transfer between the oil, condensates and the vaporm One distinct feature of the process resides in the fact that a selective condensation and a selective evaporation take place in each chamber. By this means fractions of a much closer boiling point range may be recovered than in any process heretofore used. 7

in each of'the chambers a heat balance is maintained The volume of vapors passing through the condenser. together with the volume of condensatesarid the residue passing through the separate circuits in any one chamber at any time .is substantially equal to the amount of oil flowing through each chamber. Further, the heat capacity of the vapor, condensates, and the residue in one chamber is substantially equal to the heat capacity of the oil passing thatchamber, and therefore the transfer of heat between the oil and vapors, residue and condensateswill.

the condensate circuits arranged so that the path of flow of the circuit through any one or more of the chambers may be varied, distinct temperature dlfferentials may be maintained in each chamber, and the fractionation may be so controlled that the proper proportion of vapors may beformed and condensed in each chamber. By varying the volume ofcondensate passing through the various chambers, also, a heat balance may be maintained, regardless of variations in the heats of vaporization of the difierent products and variations of thespecificheats-of the different products. y

In the fractionating tower shown in the drawings, only sixvaporizing chambers are shown. This showing is merely for illustra tive purposes and for the usual petroleum distillation, more than six chambers would be used. In any case, however, the number of the chambers willdepend upon the charactor of the fractionsavhich it is desired to separate, and upon the character of the oil.I

Although the process has been particularly described in conjunctionjwith the distillation of crude petroleum oil, it will be obvi ous that the process is *not limited to petroleum distillation, but may be readily adapted for the distillation of. practically any liquid mixtures. The process lends it-' self'readily for the distillation of coal tar oils and petroleum distillates. The process and apparatus illustrated :and described above are particularly adapted for distilling low gravity crude oil, such as Mexican and California crude petroleum, becauseby the use of the gas circuit low temperatures may be maintained and the viscosity of the oil may be controlled to allow the oil to circulate readily and flow through thestill. V

The preferred form of the invention having been thus described, what is'claimed as new is: y f q 1. A process of fractionally distilling liquid mixtures, comprising passing a liquid mixture through a series of zones maintained at progressivelyhigher temperatures, vaporizing successive portions of the mixture in said zones, fracti-onally condensing said vapors asformed by a heat interchange with said liquid in preceding cooler zones, and reducing all ofsaid condensates to substantially the temperature ofthe incoming liquid mixture by a heat transfer with the liquid in the various zones.

2. A process of fractionally"distilling liquid mixtures, comprising passing a liquid mixture through a series of zones maintained at progressively higher temperatures, vaporizing successive portions of theliquid in said zones,-tractionally condensing said vapors as formed by a heat interchange with said liquid advancing toward the zone in which the vapor is formed, collecting the condensates formed in the zones, and passing the remaining vapors into scrubbing relation with said liquid having approximately the temperature of said remaining vapors, and gradually cool ing the condensatesby passing them in, heat transferring relation to but out of contact with said liquid advancing'toivard thezones of higher temperature whereby substantially all of the sensible heat is absorbed fro id condensates. Y

3. A process of fractional'ly distilling hydrocarbon oils, comprisingpassing oil through aisseries of zones of progressively increasing temperatures, vaporizing successive portions of the oil in the zones, remov ing vapors formed in the zones'and' passing them through preceding cooler zones in heat interchanging relation to but out of contact with the oil in the said cooler zones, to immediately condense port-ions of them, passing the condensates, through the zones in heat interchange relation to but out of contact with'the oil, and controlling the flow of the them, scrubbing vapors uncondensed in one zonewith oil in the same zone, and controlling the volume of condensates in. the various zones to effect a selective condensation in each zone.

5. A process of fractionally distilling hydrocarbon oils, comprising passing through a serie'sot zones of progressivelyincreasingtemperatures, vaporizing successive portions of said oil in the zones, removing v'rfpors formed through but out of contactwith the- .oil in preceding zonesto partially condense vapors formed in the zones and passing them through preceding cooler zones in heat interchanging relation to but out of contact'with the said oil in the said cooler zones to condense portions of them immediately, passing the, condensates through the zones of lower temperaturethan said condensates inlieat interchanging relation to but out of contact with the saidioil, and varying the circulation of the said condensates through one or more of thesaid zones to control the'boiling pointof condensates condensed in the zones a 6, A process of fractionally distilling hydrocarbon oils, comprising advancing oil through a series of zones of progressively increasing temperatures and thereby vaporizing portions of said oil, passing a heating througll'lsaid zones in a path countercurrent to the path o't the advance of the 'oil through the zones, tractionally condensing portions of vapors formed in the'zones by a heat trans fer withoilin zones preceding those in whichthe thevap'ors are formed, and separately passing the condensates in heat transferring relation to oil in the. zones to reduce the con- 1 drocarbon densates to approximately the temperature of the incoming oil.

7. A process of fractionally distilling hyoils, comprising passing oil through a series of distinct heating zones having progressively higher temperatures, leading oil from the highest temperature zone to a heating still, conducting a preheated gas through the still and zones in a path countercurrent to the path of the flow of oil through the still and zones, separating vapors trom the oil in the zones, condensing vapors by a heat interchange with oil in the preceding cooler zones, and passing the condensates through the zones in a path countercurrent to the path of the flow of the oil, while they are maintained separately and in heat transferring relation to the oil. 8. Aprocess of fractlonally distilling hydrocarbon OllS, comprising passing oil through a series of distinct heating zones the sensible heat of the condensates inthe oil;

being treated withinthe said zones.

9. A process of fractionally distilling hydrocarbon oilscomprising passing oil to be distilled through a series of zones maintained at successively highertemperatures and then into a still, heating the oil in the still to produce vapors therefrom, passing a heated gas through the oil in said still, conducting said gas and vapors from said still through said zones in a path countercurrent to the flow of oil therethrough whereby portions of said oil are vaporized and portions of said vapors are condensed, and heating the oil insaid zones by passing the condensate formed in each zone through the preceding zones of the series. 7 V

10. A process of tractionally distilling hydrocarbon oil comprising passing oil through a series of zones maintained at progressively higher vaporizing temperatures, passing the vapors formed in each zone into heat transfer relation but outof direct contact with liquid oil in the preceding cooler zones whereby a series of condensates isproduced, and heating the oil flowing from zone to zone by the condensates formed in the zones of higher temperature. 7

11. A process of lt'ractionally distilling hydrocarbon oils, comprising passing oil downwardly through a series of zones maintained at progressively higher temperatures, vaporizing successive portions of oil in said zones, condensing the vapors by conducting them through zones preceding the zones in which they are formed in a, heat transferring relation to but out of contact with the oil in the zones, separating the condensates from the vapors, andmaintaining suliicient pressure in the zones to force the condensates in separate circuits upwardly through the zones.

12. A process of fractionally distilling hydrocarbon oils, comprising passing oil downwardly through a series of zones maintained at progressively higher temperatures, vaporizing successive portions of oil in said zones, passing a gas upwardly through the zones in succession, mixing the vapors with the gas and passing the mixture in heat transferring relation to but out of contact with oil in the precedingzones, separating a condensate from the gas-vapor mixture in each zone, and maintaining suificient pressure in the zones to force the condensates in separate passages upwardly through the zones preceding those in which the condensates are separated.

13. A process of tractionally distilling hydrocarbon oils, comprising passing oil in succession through a series of zones maintained at progressively higher temperatures, leading oil "from the zone of highest temperature to a heating still, mixing vapors as formed in the still and zones with -a heat transferring gas and passing the gas'vapor mixture through zones in a path countercurrent to the flow of oil through the zones, con (lensing vapors from the zones by heat transfer with the oil'in preceding zones and conducting the oil residue from the still and condensates from individual ones of said zones through other .of said zones in a path countercurrent to the flow of oil in the said zones While maintaining said condensates and res idue in heat transferring relation to but out of contact with the oil in the zones.

14. A distilling apparatus which comprises an upright column, transverse partitions in said column forming a vertical series of chambers, gravity overflow connections between the chambers to lead oil downwardly througli the chambers, said connections be ing arranged to provide a vapor space in the upper portion of each chamber, a condenser connected with each olsaid spaces and positioned in the preceding chamber, and means for conducting condensates formed in said condensers through chambers preceding the chamber in which the condensate is formed.

15. 'Ar distilling apparatus which comprises an upright column, transverse partitions in said column 'for forming-a vertical series of separatechambers, gravity overflow connections between adjacent chambers to lead oil downwardly therethrough, a heating still, means for leading oil from the last chamber oi the series to the still, a condenser mounted in each chamber, neans for leading vapors formed in each chamber into the condensers in the preceding chambers, a vapor connec- 16. A distilling apparatus which comprises.

an upright column, transverse partitions in sa d column for form ng a verticalseries separate chambers, gravity overflow connections between adjacent chambers to lead oil downwardly therethrough, a heating still, means for leading oil from the last chamber or the series to said still, a condenser in each of said chambers in contact with the oil under treatment therein, means for conducting vapors formed in one chamberdirectly into the condenser of a;precedingchamber, and means for conducting residuefrom the still. through the chambers in a path countercun rent to the path of the flow of oil therethroughf I IT. A distilling apparatus which comprises an upright column, transverse partitions in said column foriorming a vertical series or" separate chambers, gravity overflow connections between the chambers to lead oil downwardly therethrough, a "heating still, means for leading oil from the last chamber ofthe' series to said still, means for condensing oil fractions-in said chan'ibers, and means for separately conducting residue from the-still and fractions condensed in the chambers through the chambers in a path countercurrent to the path of the flow of oil therethrough. V

18. A distilling apparatus which comprises a seriesof oilvaporizingchambers, means for leading oil in succession through the said. chambers, vapor condensers in said chambers, means for conducting vapors from one chamber into condenser of a preceding chamber, means to conduct uncondenscd vapors from the condenser into the oil in the same chamber, means for heating the oil leaving the last chamber ofcthe series toany desired temierature, means for conducting vapors from said heating means to said last chamber, and a condensate passage leading from the condenser of each chamber through the preceding chambers. o

19. A distilling apparatus which comprises a series of oil vaporizing chambers, means for g oil in succession through the chama condenser unit mounted in the lower portion of each'chamber and adapted to be cooled by the oil therein, means for conducting vapors from one chamber into a condenser oi a preceding chamber, means for heating the oil leaving the last chamber of the series to any desired temperature, means for conducting vapors from said heating means to the last chamber of the series, a

condensatepassage leading from the con denser 01 each chamber through the precedlng chamber,andmeans for varying the flow of the condensate 1n passages in the chambers.

" 20. A distillingapparatus which comprises a series of oil vaporizing chambers, means for leading oil in succession through they chambers, condensers in the said chambers, means for conducting vapor from one chamber into the condenser of a preceding chamber, means for heating oil leaving the last chamber of the series to any desired temperature. means for v 1 conducting vapors rrom said heating means to the last chamber. of the series, condensate coils for conducting condensates from said condensers through preceding chambers, and

means torby-passing condensate around a portion ofthe length ofa coil within the chambers.

21. A distilling apparatusivhich comprises a series of oil vaporizing chambers, means for leading oil in succession through the chamhers, vapor condensers in the said chambers,

means for conducting vapors fromone cham- 1 her into a condenser of the preceding chainber, means for heating the oil leaving the last chamber of the series to any desired temperature, means ifor conducting vapor'from' said. heating means to said last chamber, a condensate passageleading from'the condenser of each chamber through the preceding cham 'bers, means for placing the condenser under pressure, aud a trap for introducing condensates from the condensers into their respective passages. p f

22. distilling apparatus whichcomprises an upright column, transverse partitions di vidin rsaid column into a series of chambers each having a vapor zone, means for leading. oil throughsaidchambers in succession, condensers in the said chambers, means to introduce gas into the lowermost chamber, means to conduct gas and vapor from the 1 vapor zone in one chamber into the condenser ot a chamber above 1t, means to distribute the gas and uncondensed vapor over the bottom' ofthe chamber in which the condenser is located, and means to conduct the condensates termed in-the chambers in separate passages upwardly through the chambers above those in which the condensates are formed.

A distilling apparatus which comprises an upright column, transverse partitions divldlng said column into a series of chambers each having a vapor'zone, means for leading oil through the chambers in succession, a con- I denser in each chamber, a heating still, means to lead Oll from the bottom chamber of the column to the still, means to introduce heated gas into the bottom of the still, means to conduct vapor and gas from the still into the condenser of the bottom chamber, means to conduct gasand vaporl rom the vaporzone passages upwardly through the chambers above those in which the condensates are formed.

24. A distilling apparatus which comprises an upright column, transverse partitions c ividing said column into a series of chambers, gravity overflow means for leading oil from the top to the bottom of the column While maintaininga predetermined depth of oil in each chamber, a gas distributor mounted'on the bottom of eachchamber, a condenser unit mounted in each chamber and adaptedjto be cooled by the oil therein, means for introducing a heated gas into the distributor ot' the bottom chamber, means to conduct gas and vapor from each chamber into the condenser of the chamber above it, means to conduct gas from the condenser in each chamber into the distributor of that chamber, and means for collectingcondensates separately from the condensers.

25. The process of fractionally distilling oils, which comprises passing oil through a series of distinct heating zones of progressively higher vaporizing temperatures, con ducting a heated gas through the zones in a path countercurrentto the flow of oil therethrough, passing the vapors formed in each zone into heat transfer Withthe oil in the nextpreceding cooler zones whereby a series of condensates is produced and heating the oil being passed through the zones by the condensate produced in zones of higher tempera- I ture.

26. A process of fractional distillation and condensation of oil, which comprises flowing oil to be treated through a series of vaporizing chambers maintained at successively higher vaporizing temperatures, condensing trol the boiling point of the vapors condensed in said chambers.

27. The process defined in claim 2%} in which the vapors remaining uncondenscd in a chamber 01 lower temperature are mingled With the vapors evolved from the oil in that chamher. 1

28. In the fractionaldistillation and condensation of oil, the process which comprises maintaining a series of bodies of oil at successively higher temperatures, heating the oil in certain of said bodies by indirect heat transfer with vapors and condensates from bodies of higher temperature While simultaneously condensing a portion of said vapors and bubbling the uncondensed portion of said vapors throughthe oil bodies being heated.

29. In a distilling apparatus, a vaporizing chamber, means for maintaining a body of liquid to be distilled in said chamber, means for heating the liquid in said chamber comprising independent means for bringing hot gases and liquids into heat exchange relation but out of contact with the liquid to be distilled and means for introducing a portion 01" said gases into saidchamber from the gaseous heat exchange heating means;

In testimony whereof I aifix my signature,

7 DAVID G. BRANDT.

CERTIFICATE OF CORRECTION.

Patent No. 1,713,255. Granted May 14, 1929, to

DAVID G. BRANDT.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, line 62, claim 2, after the word "with" insert the words "a portion of"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 13th day of August, A. D. 1929.

M. J. Moore, (Seal) Acting Commissioner of Patents. 

